This invention relates to apparatus for attachment of U-shaped metal clips to a tube of flexible casing material which has been filled with a viscous product. The apparatus applies clips to the casing as the filled casing-product is moving. The invention further relates to a mechanism for attaching metal clips to casing at intervals along the casing thereby sealing product within the casing in the form of separate links as the filled casing is moving continuously.
Various food products, such as sausage or cheese, are packaged in flexible, tubular casing by attaching metal clips to the filled casing at spaced intervals thereby sealing and closing the product within the casing, Klenz, U.S. Pat. No. 3,383,754 issued May 21, 1968. incorporated herewith by reference, discloses a device adapted for applying U-shaped metal clips about casing. Klenz discloses the use of a punch for driving a U-shaped metal clip through a channel against a die to form the clip about filled and gathered casing material aligned between the punch and the die. Klenz, U.S. Pat. No. 3,543,378 discloses the use of a pair of clippers arranged in tandem and cooperative with opposed, moveable, casing gathering plates defining a pair of clip channels. The gathering plates move in opposition to each other to gather filled casing material into a constricted form. Two U-shaped metal clips are then driven in channels defined by the gathering plates by punches about the gathered material to seal the ends of adjacent links of the casing. A knife then cuts the casing between the clips to separate the links defined by the clipped casing.
Other patents disclose various combinations of gathering mechanisms for gathering casing prior to attachment of the clip or clips, including Klenz U.S. Pat. No. 3,583,506; Dobbert, U.S. Pat. No. 3,783,583; and Velarde, U.S. Pat. No. 4,001,926.
Various mechanisms have been suggested for improving the efficiency and speed of operation of clipping mechanisms when forming links of product in a continuous or assembly line operation. Andre, U.S. Pat. No. 3,795,058 discloses a single clipper mounted at a work station of rotating table. The table moves intermittently from station to station between operations performed at each station, including a clip attachment station. Andre, U.S. Pat. No. 4,578,928 discloses a circular table wherein filled casing material is transported from station to station for ultimate attachment of the clip. Ailey, U.S. Pat. No. 4,189,897, discloses a similar multiple station apparatus.
Evans et al., U.S. Pat. No. 4,821,485 disclose apparatus for attaching clips to form separate links in an operation wherein the filled casing is continuously moving in a circular pattern with the filed casing being gathered and clipped as the product and casing move continuously by and through the apparatus. The various operational stations move with the casing in a continuous circular motion about a center pivot and the various gathering and clipping operations are performed as the apparatus rotates about the pivot in a single direction.
The need has remained for a high speed continuously operating packaging device for attachment of metal clips to flexible, generally cylindrical, continuously moving casing filled with a viscous material. Such a need has been considered desirable to form links of various diameter and length filled with various materials in a continuous operation.
In a principal aspect, the present invention is an improved mechanism for sealing filled and continuously moving casing in discreet links or lengths. The apparatus includes a frame on which a reciprocating clipper assembly is mounted. The clipper assembly reciprocates continuously back and forth between a first or casing entry station and a second or casing exit station. Flexible casing, which has been prefilled with viscous material, enters the apparatus at the first station and is discharged from the second station. In the region between the first and second stations, the clipping assembly is designed to reciprocate at the same speed or synchronously with the rate of movement of the filled casing material moving forward between the first and second stations.
As the clipper assembly moves forwardly with the filled casing material, it effects gathering of the casing in order to form a necked portion thereof. The gathering operation includes voiding of a certain portion of the casing by and between a pair of gathering plates which initially constrict the casing and the separate to void the viscous filling material in the casing from the region of the constriction. The gathering plates separate or spread to ensure that a length or tail of constricted or necked casing is provided.
A pair of spaced, U-shaped metal clips is then applied to the necked casing by clipper subassemblies which are positioned intermediate the spaced gathering plates. The clips are applied simultaneously by the clipper subassemblies to the necked casing xe2x80x9con the flyxe2x80x9d as the casing and clipper assembly move between the first and second stations. Thereafter, optionally, the clipper assembly effects a cut or severance of the casing between the attached metal clips so that separate links are formed. The filled casing, having the clips attached thereto, is next released at the second station.
The clipping assembly then reciprocates or moves in the reverse direction from the second station back to the first station without impeding the continuous forward movement or progress of the filled casing between the first and second stations. Upon arrival at the first station, the clipper assembly again begins its synchronous movement with the filled casing to effect attachment of further clips thereto.
Thus, it is an object of the invention to provide an improved packaging device for filling flexible tubular casing filled with a viscous material.
A further object of the invention is to provide an improved packaging device with apparatus for attachment of U-shaped metal clips to flexible tubular casing.
Yet another object of the invention is to provide a continuously operating packaging device adapted to receive tubular casing material filled with a viscous product as that filled casing moves uninterruptedly and continuously in a generally linear direction.
Yet another object of the invention is to provide a clipper assembly which reciprocates between an entry station and an exit station and, which during movement from the entry station to the exit station, effects voiding of a section of the filled casing and attachment of one or more clips thereto.
Yet another object of the invention is to provide a packaging device which is capable of manufacture of a wide range of lengths of link product.
Another object of the invention is to provide an improved clip attachment mechanism having simplified construction and which is compact, yet which permits extremely high speed operation relative to prior art packaging devices:
These and other objects, advantages and features of the invention All be set forth in the detailed description which follows.